The present invention relates to a method and a device for measuring the non-linear coefficient γ and/or the dispersion coefficient β2 of an optical fiber in a data transmission path by four-wave mixing.
The precise knowledge of non-linear effects in optical fibers is particularly necessary in the case of integration of older fibers in an optical data transmission path with high data rates or high power or in the case of a WDM system, due to the signal distortion occurring there.
A similar method and a similar device are known from international patent application WO 98/57138 submitted by the applicant. In this method, however, measurements are required at both ends of the optical fiber in question, including the collection of data at one or the other end of the fiber. This is very expensive, particularly in the case of optical fibers which already have been laid over a number of kilometers, as account must be taken of the corresponding looping, in order to be able to analyze the data together.
An object of the present invention is, therefore. to develop a method and a device, which allow the non-linear coefficient γ and/or the dispersion coefficient β2 of an optical fiber to be measured, by measuring at only one end of the optical fiber.